A complex low pressure system tracked across the Great Lakes Region. The low brought warm air into the area above a persistent cold layer near the surface. These conditions resulted in snow, sleet and freezing rain. The worst of the storm occurred in parts of north-central and northeast Wisconsin where nearly a quarter of an inch of ice accumulated along with the snow and sleet. Dozens of vehicles slid off roads that started to become slippery during the evening of the 3rd.